Earth boring apparatus



6 Sheets-Sheet l HVVTHWDORS I ATTORNEYS Dec. 23, 196E c, LAWRENCE ET AL EARTH BORING APPARATUS Filed Aug. 8, 1967 JAMESCLJFTONLAWRENCE WILLIAM HAUTH HAMILTON wwww o Q Q 0 QQ/Q OOQ mm 6 Dec. 23, 1969 J. c. LAWRENCE ET AL 3,485,309

EARTH BORING APPARATUS Filed Aug. 8, 1967 6 Sheets-Sheet-B JAMas CLIFTON LAWRENCE WILLIAM HAUTH HAMILTON ATTORNEY 5 Dec. 23, 1969 J, c. LAWRENCE ET AL 3,485,309

EARTH BORING APPARATUS Filed Aug. 8, 1967 6 Sheets-Sheet 3 INVENTORS JAMES CLIFTON LAWRENCE WILLIAM HAUTH HAMILTON ATTORNEYS EARTH BORING APPARATUS Filed Aug. 8, 196'? u N O O o o [N 44 I A 62 O o s1 0 O O 93 i o o i 92 o o o 4 o O 5 0 N s 94 I55 I52 0 0 I54 O P |5 3 I59 6 I58 I57 I59 44 |43 '57 6 Sheets-Sheet 4 INVENTORS JAMES CLIFTON LAWRENCE WILLIAM HAUTH HAMILTON ATTORNEYS Dec. 23, 1969 J c, LAWRENCE ET AL 3,485,309

EARTH BORING APPARATUS Filed Aug. 8, 1967 6 Sheets-Sheet 5 I H mvsmons JAMEs CLIFTON LAWRENCE WILLIAM HAu-r-H HAMILTON ATTORNEYS 3, 9 J, c. LAWRENCE E L I 3,485,309

EARTH BORING APPARATUS Filed Aug. 8, 196? 6 Sheets-Sheet 6 E INVENTORS JAMES CLIFTON LAWRENCE WILLIAM HAUTH HAMILTON BY al V ATTORNEY 5 United States Patent US. Cl. 175230 11 Claims ABSTRACT OF THE DISCLOSURE An earth boring apparatus comprises an anchor tube assembly selectively anchored at its forward end within a pilot bore at a point within the rock or other material to be cut ahead of a rotating main cutter head that is axially slidable along the anchor tube assembly and the rotating cutter head is pulled forwardly into the material face toward the anchored front end of the anchor tube assembly. The anchor tube assembly near its rear end carries rib jacks engaging the tunnel wall.

Thrust reaction forces caused by the main cutting head action are transmitted directly to the rib packs by a system including levers pivoted on the anchor tube assembly connected by thrust links to the rib jacks and mounting thrust cylinders connected for urging the cutting head forwardly along the anchor tube assembly.

HISTORY AND SUMMARY OF INVENTION The invention relates to earth boring, for example hard rock tunneling, machines of the type disclosed in US. Reissue Letters Patent No. 24,965 issued Apr. 11, 1961 wherein the front end of a pilot or anchor tube is anchored within a pilot bore ahead of the face to be cut by a main cutter, and means reacting from the anchored front end of the tube draws the rotating main cutter toward that anchored end to cut the tunnel. In the early machines of this type all of the thrust reaction forces incident to cutting by the main cutter were taken at the anchored front end of the tube. In the present invention the anchor tube also carries rib jacks extensible for anchoring to the tunnel walls, and thrust reaction forces incident to cutting by the main cutter are transmitted directly to the rib jacks, and this is the major object of this invention. Other objects of the invention include details of mechanism for carrying out the foregoing including a system of levers and links for connecting the main cutter thrust cylinders directly to the rib jacks, and other features as will appear in the claims.

BRIEF DESCRIPTION OF DRAWINGS FIGURE 1 is a partial side elevation in section showing the forward end of a machine constructed according to a preferred embodiment of the invention;

FIGURE 2 is a partial side elevation partly broken away and in section showing a rearward continuation of the machine of FIGURE 1;

FIGURE 3 is a partial side elevation partly broken away and in section showing the same machine in rearward continuation of FIGURE 2;

FIGURE 4 is an end elevation in section substantially along line 4-4 of FIGURE 2;

FIGURE 5 is an enlarged fragmentary side elevation partly broken away and in section showing machine detail;

FIGURE 6 is an enlarged fragmentary top plan view partly broken away and in section showing rib jack details and connections.

PREFERRED EMBODIMENTS The machine of the invention comprises a normally 3,485,309 Patented Dec. 23, 1969 stationary support structure 11, which during operation remains non-rotatable but may be advanced periodically along the tunnel on wheels, skids or the like (not shown). The support structure comprises a relatively large gear housing 12 and a forwardly extending hollow boss 13.

A main cutter head assembly 14 is rotatably mounted on the support structure by bearing assemblies 15 and 16, for rotation about an axis indicated at A in FIGURE 1. Head 14 carries a series of cutters 17 that, when the head is rotated, engage the front face 18 of the tunnel being cut, usually rock, and form the main tunnel indicated at 19. Cutters 17 are sufiicient in number and so distributed for the purpose.

A hollow anchor tube assembly 21 is non-rotatably but axially slidably mounted on support structure 11, as by the cylindrical slide guide 22, the internally splined member 23 and the cylindrical slide guide 24, and details of this mounting will later appear as an important part of the invention. As shown in FIGURE 1, the forward end 25 of anchor tube 21 projects out of the support structure into a pilot bore 26 in the rock being cut, and a radially expansible anchor unit 27 is mounted on that forward end of the anchor tube. The function of anchor unit 27 is to radially expand when selectively actuated by the operator to displace gripping elements 28 into gripping engagement with the pilot bore wall to fix anchor tube 21 against both axial and rotational movement, so that in effect the anchor tube is rigid with the rock being cut.

This anchor assembly may be of any suitable type, and preferably it is of the type disclosed in the pending application of James C. Lawrence and William H. Hamilton, Ser. No. 539,354, filed Apr. 1, 1966 for Anchor Assembly, and reference is made to that application for any further necessary disclosure of the anchor assembly and its controls.

A rotatable pilot cutter assembly 31 comprising a hollow shaft 32 terminating at the front end of pilot bore 26 in a cutting bit 33 extends relatively freely through the hollow anchor tube assembly. Bit 33 may be of any suitable type non-rotatably secured, as by the key and slot connection shown at 34, to pilot shaft 32. The anchor assembly 21 and the pilot cutter assembly 31 are both coaxial with the main cutter assembly, on the axis A which is usually at right angles to the tunnel face 18 being cut by the main cutter.

The main cutter head assembly 14 is rotated about axis A during operation by a ring gear 41 bolted at 42 to a radial flange 43 thereof within gear case 12. Gear 41 is driven by the combined effort of a series of motors 44 all mounted on gear housing 12. Preferably these motors are mounted in opposed pairs at opposite sides of housing 12, each pair being drive connected to a shaft 45 mounted on bearings 46 within the gear housing and having fixed thereto a drive pinion 47 meshed with ring gear 41. The axes of pinion gears 47 are parallel to the ring gear axis and are disposed on a circle around the ring gear axis. When the main cutter is to be rotated, all of the motors 44 are simultaneously actuated, by suitable controls (not shown). Motors 44 are preferably hydraulic motors.

Referring to FIGURE 2, the inner side of gear housing 12 and the rear face of the ring gear mounting flange have secured thereon parallel hard surfaced annular bearing plates 51 and 52 between which is disposed an annular thrust bearing roller assembly 53 concentric with axis A. Thrust forces incident to advancing the main cutter 14 against rock face 18 during cutting are transmitted through the bearing 51-53 to the support structure 11. A thrust bearing ring 54 is provided between the front face of flange 43 and the adjacent side of the gear housing.

Referring to FIGURES 2 and 4, the member 23 rigid the support structure 11 is formed with a series of I At its rear end, pilot shaft 32 has a reduced diameter internal spline teettril-fihaeareponstantlymeshed with portion '121'" on which is fixed -a collar'122 in spaced relaa series of longer external spline teeth 62 on the anchor tube 21. These teeth prevent 'the anchor tube from rotatingfabout axisiA but"permitfaxiaLsliding of'the anchor tube on that axis when-*desiredZ Teeth 62 are sufficiently long' in-the' axial direction to remain fully'meshed with teeth 61 during allrelative axial'rnovement between the anchor tube-Tand the support' structure. An annular seal 63' carried byrearwardly extending collar 64 on the support-structureslidablyengages the anchor tube. Referring to FIGURES 2' and 6; the anchor-tube assembly-21 comprisesaalever pivot assembly which includes :an annular adapter71rigidly secured to the rear end"of-v the :anchorf tube,- as by screws' l3, an' annular pivot"lever-r'support member :74'secured as by screws 75 to adapter 71, and a tubular rearwardly projectin'gsection 76'. secured as-by screws 77 -to member 74: Adapter--71, member 74 and section 76- are'concentric with: axis A. -.Lever support member 741's formedat top and-bottom 'withopposed' concentric cylindrical recesses 78 rotatably receiving the cylindricaltrunnions 79 of parallel generally horizontal'rooker levers 81, one above and one below the anchor tube assembly. Each trunnion is preferably" a separate element secured to its 'lever byscrews 82.

As shown in FIGURE 6, two main hydraulic thrust cylinders 83 and 84 are mounted on and between levers 81. Each cylinder has opposed arbors 85 extending rotatably into levers 81, so that cylinders 83 and 84 are rockable about axis 86 located the same distance from the trunnion axis indicated at 87 in FIGURE 6 which axis is essentially vertical and perpendicularly intersects axis A.

Each cylinder 83 and 84 contains a slidable piston shown at 88, and pistons 88 are rigidly secured to thrust rods 89 and 91 which (FIGURE 5) are pivotally connected at 92 and 93 respectively to thrust ring 94 which is a rigid part of support structure 11.

The pivotal linkage consisting of thrust ring 94, the thrust cylinder and thrust rod assemblies 83, 89 and 84, 91 and levers 81 defines a parallelogram.

As shown in FIGURES 2 and 6, the outer ends of levers 81 are formed with inwardly extending bosses 95 mounting parallel shafts 96 equidistant from axis 87. Thrust links 97 of equal length are pivoted on shafts 96 at one end and are pivoted at 98 at their other ends to the ends of plungers 99 of an annular rib jack frame 100. Plungers 99 are mounted in hydraulic cylinders 101 rigidly connected together on frame and coaxially disposed on opposite sides of the anchor tube assembly. Also pivoted upon the plungers 99 and 98 are tunnel wall engaging shoes 102 having outer arcuate surfaces covered with a replaceable liner of friction material 103 adapted-for gripping the tunnel wall.

Cylinders 101 are rigidly secured upon opposite sides of an'annular member 104 that is non-rotatably connected to anchor tube section 76 as by meshed splines at 105. As shown'in FIGURE'3, opposed vertical cylindrical trun- 1 i cutter 4.-

nions 106 on member 104 extend into a bearing support a 107 on frame -100 having an antifriction bearing liner 108, whereby with the rib jacks anchored the anchor tube assembly 21 may be adjusted about the vertical axis of trunnions 106 for steering of the machine as will appear. The vertical axis of trunnions 106, indicated at 109 in FIGURE 6, is parallel to axis 87 and both of these axes intersect axis A.

1 Rearwardly of the rib jack assembly 100, a pilot drive unit 111 comprising a housing'112 is secured on the rear end of the'anchor tube assembly. A pair of hydraulic motors 113 are mounted on housing 112 and their output shafts extendinto housing 112 and carry gears (not shown) meshed with a pilot. drive gear 115 which is slidably splined on pilot shaft 32' at 116. Alternatively the non-rotatable slidable connection at 116 may comprise a pair of diametrically opposed integral keys on the shaft 32 extending into internal keyways in the gear 115.

tion to housing 112. An annular frame 123 is rotatably mounted on collar 122 by the tapered roller bearing assembly 124 which also serves asa-thrust bearing. As shown in FIGURE 3, frame .123 supports a air .of pilot thrust cylinders.1 25 .-and-126 from which .extend reciprocable piston rods. 1-27 and.128'pivotally connected at129 and 131 to opposite sides of housing 112'. A fiexibleboot 132 extends between housing'112 and collar'12'2 to surround the length of pilot' shaft 32 therebetween in all relative axial positions of shaft 32 and the anchor tube.

As shown in FIGURE3, the passage through shaft 32, which. conducts cut material from pilot bore 26 through the machine is'connected by a rotatable coupling 141 to a'fiexible-conduit' 1 42-to a material discharge system 143 that-as 'shown'in FIGURE-1, includes'a screw conveyor 144 for rearwardly-rnoving material dislodged by' the main Referring to 'FIGURE"4;"the thrust ring 94 of the support structure mounts three jacks'151, 152 and 153. Each jack comprises a cylinder 154 fixed to'the thrust ring and containing a hydraulic fluid'chamber 155 within which is slidable a'plunge'r 156 carrying on its outer end a tunnel wall engaging shoe 157. The upper jack 151 is substantially vertical to engage the tunnel roof, and the lower two jacks 152 and 153 diverge to engage the tunnel floor atopposite sides of the material conveyor assembly. These jacks selectively anchor the support structure 11 to the tunnel.

As shown in FIGURE 2, and partially in FIGURE 4. each lower cylinder 154 may have opposed arbors 158 pivotally mounting a dual arm lever 159 that carries a tunnel floor engaging wheel 161 at one end and is pivotally connected at 162 to the extensible cylinder 163 of a hydraulic cylinder unit having its piston rod 164 pivoted upon support structure 11 and 165. Cylinders 163 may selectively retract wheels 161 from engagement with the tunnel under certain operational conditions as steering.

In operationas when tunneling hard rock a pilot bore 26 is cut, sometimes by a separate drill but usually by the pilot cutter 33 by rotating shaft 32 about axis A under the power of motors 113, and the machine is disposed in the position shown in FIGURE 1 wherein the anchor assembly projects within the pilot bore and the main cutter head is brought up to the rock face 18 to be cut. Where the pilot bore is cut by bit 33 the shaft 32 is rotated by motors 113 while being advanced by cylinders 125, 126 forwardly through the hollow anchor assembly.

The pilot anchor 27 is expanded until shoes 28 firmly grip the pilot bore walls, and this anchors the anchor tube assembly 21 rigidly to the material to be cut. The opposed rib jacks of FIGURE 6 are extended outwardly until shoes 102 firmly grip the side walls of the tunnel, this being accomplished by introducing hydraulic fluid under suitable control into cylinders 101 to outwardly displace plungers 99.

The anchor tube assembly 21 is immovable, being anchored both at 27 and at the rib jacks. Jacks 151-153 are released. Advance of the main cutter head 14, rotated by motors 44, is effected by forward displacement of support structure 11 along the anchor tube assembly by cylinders 83, 84 acting through thrust rods 89, 91 which are connected to thrust ring 94 of the support structure. As cutter head 14 advances to the left in FIGURE 1, it cuts the material at face 18 and therefore extends the tunnel to the left in FIGURE 1. 1

During the cutting operation by main cutter head 14, tremendous torque is exerted to rotate the head and tremendousthrust is exerted to advance into the rock face. The torque reaction forces are transmitted through the splined connection at 61, 62 from support structure 11 to the stationary anchor tube assembly. Thrust reaction forces incident to forward movement of the head 14 are transmitted directly to the rib jacks by links 97 so that both the anchored front end of the assembly 21 at 27 and the rib jacks share the thrust load, and in case one of them is insecure the other will hold. It has been found in the invention that the foregoing arrangement so distributes the forces incident to operation that where operating in formation of different or variable densities and holding capability sufiicient thrust reaction can be maintained, which is essential for efiicient operation. It has also been found that the support structure can be made of lighter construction without deformation.

As the main cutter head moves forwardly, the pilot shaft usually continues to be driven to cut the pilot bore ahead. As soon as the main cutter has completed a forward stroke of predetermined length, jacks 151-153 are again anchored to the tunnel wall, anchor assembly 27 and the rib jacks are released and the anchor tube assembly is slidably displaced through the support structure to a new position such as in FIGURE 1 whereupon the foregoing cycle is repeated.

The apparatus of the invention may be accurately shifted to change the direction of cutting of the main cutter head in the same manner as described and claimed in the copending application of James C. Lawrence Ser. No. 416,075 filed December 4, 1964 for Steering Methods and Apparatus. The forward anchor unit 27 is expanded to anchor the front end of the anchor tube assembly within the pilot bore and, with jacks 151-153 released the opposed plungers 99 are selectively extended difierent distances to lock shoes 102 to the bore wall. Trunnions 106 allow the anchor tube assembly to turn about the vertical axis on the rib jack frame as the anchor tube assembly swings about the forward anchor 27. Thus the anchor assembly will be displaced at an acute angle with respect to the axis of the pilot and main bores, and when the main cutter head is now advanced the main bore is cut on the new axis of the anchor tube assembly. This shift of the cutting axis is made incrementally until the desired change in direction has been made, as explained in said application to which reference is made for any detail necessary to understand the foregoing.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for cutting a main bore in earth, hard rock and like material comprising a support structure, a main cutter head rotatably mounted on said structure and adapted to engage and cut a face in said main bore, means for rotating said main cutter head, an anchor assembly slidably connected to said structure and having selectively expansible means on its forward end for selective anchoring within a pilot bore at a point within the material ahead of the face to be engaged by said main cutter head, laterally extensible anchor devices mounted on said anchor assembly rearwardly of said main cutter head adapted to rigidly engage the walls of said main bore whereby said anchor assembly may be anchored both within the pilot and main bores while the main bore is being cut by the main cutter head, means reacting from said anchored anchor assembly for advancing said support structure carrying said rotating main cutter head toward said main bore face, and lever means pivoted on said anchor assembly, a plurality of fluid pressure responsive thrust cylinders mounted on said lever means and having slidable thrust rods operably connected to said support structure, and thrust links operably c nnecting said lever means directly to said anchor devices.

2. In the apparatus defined in claim 1, mechanism carried by said anchor assembly for transmitting the thrust reaction forces incident to advance of said main cutter head into said face directly to said anchor devices.

3. In the apparatus defined in claim 1, said support structure having a non-rotatable axially slidable connection with said anchor assembly.

4. In the apparatus defined in claim 1, said means for advancing the support structure toward said face comprising fiuid pressure thrust cylinder means carried by said anchor assembly and operably connected to both said support structure and said anchor devices.

5. In the apparatus defined in claim 1, said anchor assembly comprising a hollow tube having an axially splined slidable connection with said support structure, a pilot shaft extending rotatably through the tube and having a pilot bore cutter on its forward end outside the tube, means mounted on said tube for rotating said pilot shaft, and means on said tube for axially displacing said rotating pilot shaft with respect to said tube.

6. In the apparatus defined in claim 1, said means for rotating said main cutter head comprising a motor driven ring gear unit rotatably mounted in said support structure, and a thrust bearing between said gear unit and said support structure.

7. In the apparatus defined in claim 1, rib jacks independent of said anchor devices for anchoring said support structure to the bore wall when the anchor assembly is displaced slidably through said support structure to a new forward position within the pilot bore.

8. In the apparatus defined in claim 1, each of said anchor devices comprising a bore wall engaging member mounted at the outer end of a plunger slidably in a hydraulic cylinder, a frame on which both of said cylinders are fixedly mounted, an annular member non-rotatably mounted on said anchor assembly, and means providing a vertical axis trunnion connection between said annular member and said frame.

9. In the apparatus defined in claim 8, said cylinders being pivoted on said lever means, and said links being pivoted at opposite ends to said lever means and to said anchor devices outside said hydraulic cylinders.

10. In the apparatus defined in claim 1, lever means comprising upper and lower levers pivoted at their midsections on a vertical axis on said anchor assembly, a pair of thrust links of equal length pivoted at opposite ends to adjacent ends of said levers and to said anchor devices, a pair of thrust cylinders intermediately pivotally mounted on said lever means between the levers on axes that are equidistant from the pivot axis of the levers to the anchor assembly, and parallel thrust rods slidably extending from the cylinders and pivotally connected to said support structure.

11. In the apparatus defined in claim 10, the axes of the pivots between said lever and said links, cylinders and anchor assembly lying in a plane.

References Cited UNITED STATES PATENTS 2,988,348 6/1969 Robbins 29931 3,345,108 10/1967 Newman et al. 299-31 3,376,942 4/1968 Van Winkle -230 3,386,520 6/1968 Lawrence et al 175230 JAMES A. LEPPINK, Primary Examiner R. E. FAVREAU, Assistant Examiner US. Cl. XR. 

